Cost-effectiveness analysis of darbepoetin after switch from epoetin-beta in patients on hemodialysis: an Italian single-center retrospective study

Abstract

Darbepoetin (DARB), a human erythropoietin with improved pharmacological parameters (longer half life and a dose-response relationship independent from the route of administration) is a new treatment option for chronic nephropathy-induced anemia that in many Italian dialysis centers is substituting older erythropoietins, mainly due to greater ease of use. At current prices and at the theoretical and recommended 200:1 dose conversion factor, DARB pharmaceutical cost ranges from –9% to +17% of EPO cost. In this monocentric study, real drug consumption and related actual costs of a pre-switch semester with EPO were analysed and compared to the first two post-switch semesters with DARB therapy. Furthermore, erythropoetic response was recorded and related to drug exposition levels, in order to establish a real life EPO:DARB dose conversion factor. In this experience, the conversion factor was estimated in at least 250-280:1, depending on the method adopted for the estimation. The initial dose, chosen on the basis of the recommended conversion factor, induced an excessive erythropoietic response, which was generally followed by a dose reduction and successive titration to target desired Hb levels, generating the spiraliform dose-response curve associated with delayed feed-back mechanisms. The pharmacoeconomical analysis, conducted in the perspective of the public health service, indicated that the choice of substituting DARB for EPO in the treatment of chronic kidney failure-associated anemia is univocally convenient, the former being less costly and more effective.